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| author | Stefan Liebler <stli@linux.ibm.com> | 2023-11-21 13:33:03 +0100 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.ibm.com> | 2023-11-30 13:31:23 +0100 |
| commit | 807849965bbdeaa9b0a8f675d098efc520eeaaa8 (patch) | |
| tree | 3438d290535be05ecdee893072c1fe790a9105f2 /sysdeps | |
| parent | 7b12776584c51dbecb1033e107f6b9f45de47a1b (diff) | |
| download | glibc-807849965bbdeaa9b0a8f675d098efc520eeaaa8.tar glibc-807849965bbdeaa9b0a8f675d098efc520eeaaa8.tar.gz glibc-807849965bbdeaa9b0a8f675d098efc520eeaaa8.tar.bz2 glibc-807849965bbdeaa9b0a8f675d098efc520eeaaa8.zip | |
Avoid padding in _init and _fini. [BZ #31042]
The linker just concatenates the .init and .fini sections which
results in the complete _init and _fini functions. If needed the
linker adds padding bytes due to an alignment. GNU ld is adding
NOPs, which is fine. But e.g. mold is adding traps which results
in broken _init and _fini functions.
Thus this patch removes the alignment in .init and .fini sections
in crtn.S files.
We keep the 4 byte function alignment in crti.S files. As the
assembler now also outputs the start of _init and _fini functions
as multiples of 4 byte, it perhaps has to fill it. Although GNU as
is using NOPs here, to be sure, we just keep the alignment with
0x07 (=NOPs) at the end of crti.S.
In order to avoid an obvious NOP slide in _fini, this patch also
uses an lg instead of lgr instruction. Then the emitted instructions
needs a multiple of 4 bytes.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/s390/s390-64/crti.S | 2 | ||||
| -rw-r--r-- | sysdeps/s390/s390-64/crtn.S | 2 |
2 files changed, 1 insertions, 3 deletions
diff --git a/sysdeps/s390/s390-64/crti.S b/sysdeps/s390/s390-64/crti.S index 11ab75e8d9..4c8246da26 100644 --- a/sysdeps/s390/s390-64/crti.S +++ b/sysdeps/s390/s390-64/crti.S @@ -85,7 +85,7 @@ _init: .type _fini,@function _fini: stmg %r6,%r15,48(%r15) - lgr %r1,%r15 + lg %r1,120(%r15) aghi %r15,-160 stg %r1,0(%r15) larl %r12,_GLOBAL_OFFSET_TABLE_ diff --git a/sysdeps/s390/s390-64/crtn.S b/sysdeps/s390/s390-64/crtn.S index 0eabcb346c..6bb1bc9dcf 100644 --- a/sysdeps/s390/s390-64/crtn.S +++ b/sysdeps/s390/s390-64/crtn.S @@ -37,13 +37,11 @@ corresponding to the prologues in crti.S. */ .section .init - .align 4 lg %r4,272(%r15) lmg %r6,%r15,208(%r15) br %r4 .section .fini - .align 4 lg %r4,272(%r15) lmg %r6,%r15,208(%r15) br %r4 |